Information processing apparatus, image forming apparatus, and non-transitory computer readable medium

ABSTRACT

An information processing apparatus includes: a processor is configured to: read an image of at least one of a first surface or a second surface of a medium with the medium folded; discriminate whether the image is of the first surface or the second surface based on an identification image in the image; specify, based on the image, a surface on which a folding deviation occurs; and determine a correction direction of the folding deviation according to whether the surface on which the folding deviation occurs is the first surface or the second surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 fromJapanese Patent Application No. 2020-125719 filed Jul. 22, 2020.

BACKGROUND (i) Technical Field

The present disclosure relates to an information processing apparatus,an image forming apparatus, and a non-transitory computer readablemedium.

(ii) Related Art

Attempts have been made to automatically detect a folding deviationamount at a folding position where a medium is folded by a foldingdevice in order to adjust the folding position. Such automatic detectionmethods include a method of detecting a folding length of a foldedmedium, and a method of detecting a deviation amount at a sheet edge ofthe folded medium.

For example, JP-A-2016-113284 discloses a recording medium foldingsystem in which when a manually fed recording medium is folded, therecording medium may be folded in a predetermined folding mannerregardless of a front or back side of the recording medium.

SUMMARY

However, when a method of detecting the deviation amount of the foldingposition of the medium still folded is not able to determine whichsurface of the medium is being read, a direction in which a foldingdeviation occurs cannot be discriminated, and a correction directioncannot be specified.

Aspects of non-limiting embodiments of the present disclosure relate toan information processing apparatus, an image forming apparatus, and anon-transitory computer readable medium that are capable of specifying acorrection direction of a folding deviation amount when a correctionamount of a folding position of a medium folded by a folding device isto be output.

Aspects of certain non-limiting embodiments of the present disclosureaddress the above advantages and/or other advantages not describedabove. However, aspects of the non-limiting embodiments are not requiredto address the advantages described above, and aspects of thenon-limiting embodiments of the present disclosure may not addressadvantages described above.

According to an aspect of the present disclosure, there is provided aninformation processing apparatus including: a processor is configuredto: read an image of at least one of a first surface or a second surfaceof a medium with the medium folded; discriminate whether the image is ofthe first surface or the second surface based on an identification imagein the image; specify, based on the image, a surface on which a foldingdeviation occurs; and determine a correction direction of the foldingdeviation according to whether the surface on which the foldingdeviation occurs is the first surface or the second surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiment(s) of the present disclosure will be described indetail based on the following figures, wherein:

FIG. 1 is a block diagram showing a functional configuration of an imageforming apparatus;

FIG. 2 is a schematic diagram of the image forming apparatus accordingto an exemplary embodiment;

FIG. 3 is a flowchart of an example of a folding position adjustmentprocess;

FIGS. 4A to 4C are diagrams showing examples of menu screens in thefolding position adjustment process;

FIG. 5 is a diagram showing an example of a guide screen that prompts auser to place an adjustment sheet on a platen glass;

FIGS. 6A to 6C are diagrams showing an example of reading a half-foldedsheet;

FIG. 7 is a table showing a relationship among lines obtained by imageanalysis, a sheet edge(s), and a folding line(s);

FIGS. 8A to 8C are diagrams showing an example of a folding manner thatdoes not allow detecting of a folding deviation amount unless the sheetis unfolded;

FIGS. 9A to 9F are diagrams showing examples of the sheet foldingmanner;

FIG. 10 is a flowchart of an example of a process of determining acorrection direction when an image of only one of first and secondsurfaces of the sheet is read;

FIG. 11 is table showing a relationship among identification imagesobtained by the image analysis, a first surface, and a second surface;

FIG. 12 is a flowchart of an example of a process of determining acorrection direction when images on the first and second surfaces of thesheet is read;

FIGS. 13A and 13B are diagrams showing an example of a state in which atri-folded sheet on which identification images are formed is unfolded;

FIGS. 14A and 14B are diagrams showing examples of front and backsurfaces of a 6-page accordion folded sheet on which identificationimages are formed; and

FIGS. 15A to 15F are diagrams showing examples of the identificationimage formed on the sheet.

DETAILED DESCRIPTION

1. Configuration

FIG. 1 is a block diagram showing a functional configuration of an imageforming apparatus 1 according to an exemplary embodiment. The imageforming apparatus 1 of the present exemplary embodiment performs (i) aprocess of receiving, from a user interface (hereinafter referred to asa “UI”), an instruction to fold a sheet, (ii) a process of forming animage on the sheet, (iii) a process of folding the sheet, (iv) a processof reading (that is, scanning) the image formed on the sheet, (v) aprocess of detecting a folding position of the sheet, and (vi) a processof adjusting the folding position of the sheet. Here, the “foldingposition” refers to a position where the image forming apparatus 1 foldsthe sheet. The “sheet” is an example of a medium.

The image forming apparatus 1 includes a controller 101, a storage 102,a UI 103, an image forming unit 104, an image reader 105, adiscrimination unit 106, a specifying unit 107, a determination unit108, a detector 109, and a folding unit 110. The controller 101 executesvarious processes according to a program stored in the storage 102. Thecontroller 101 is connected to the UI 103, the image forming unit 104,the image reader 105, and the folding unit 110, and controls theseunits. The “folding unit” is an example of a folding device. Thecontroller 101 is an example of an information processing apparatus. Thecontroller 101 includes a processor such as a central processing unit(CPU). The storage 102 stores the program to be executed by thecontroller 101, information related to a folding manner, and informationobtained in the folding position adjustment process. The storage 102includes a recording device such as a read only memory (ROM), a randomaccess memory (RAM), or a flash memory. The UI 103 provides the userinterface. Specifically, the UI 103 displays a screen related to afunction of the image forming apparatus 1, such as a screen related tothe folding position adjustment process, and a screen for receiving anoperation input by a user. The UI 103 includes a display device such asa liquid crystal display, and an input device such as a touch screen.

The controller 101 includes the discrimination unit 106, the specifyingunit 107, the determination unit 108, and the detector 109. Thediscrimination unit 106 discriminates which surface (that is, a firstsurface or a second surface, which will be described later) the readimage is. The specifying unit 107 specifies a surface on which a foldingdeviation occurs. The determination unit 108 determines a correctiondirection of a folding deviation amount in a folding position adjustmentprocess. Here, the “correction direction” refers to a direction in whichthe folding deviation amount is reduced, that is, a direction in whichan actual folding position is moved. The “folding deviation amount”refers to a distance (length) between an actual folding position and areference folding position. The “reference folding position” refers to adesired folding position of a sheet. The phrase “folding deviationoccurs” refers to that a difference between the actual folding positionand the reference folding position is equal to or greater than athreshold value. A “surface on which the folding deviation occurs”refers to a surface on which the folding deviation can be explicitlyobserved in the read image. The reference folding position is definedfor each folding manner. For example, the reference folding position isa position at which the sheet is equally divided into plural areas. The“actual folding position” refers to a position of a fold actually formedon the sheet in the folding process performed by the folding unit 110.The detector 109 detects the folding deviation amount. Furthermore, thedetector 109 calculates an adjustment value for adjusting the foldingposition. The image forming unit 104 forms an image on the sheet. Theimage reader 105 reads a surface condition of the sheet as an image. Itis noted that the “surface condition” includes the image formed on thesheet. The folding unit 110 folds the sheet based on the instructioninput by the user. For example, the folding unit 110 has a function ofcreating a booklet by stacking plural sheets, saddle stitching thesheets, and then folding the sheets in half.

FIG. 2 is a schematic diagram showing the image forming apparatus 1according to the exemplary embodiment. The image forming apparatus 1includes a transport path 20, trays 26, feed rollers 28, a manual feedtray 30, and an automatic transport unit 44. The transport path 20 is apath that transports a sheet from the tray 26 to the folding unit 110.For example, plural rollers and motors that drive the rollers areprovided on the transport path 20. One end of the transport path 20 isconnected to each tray 26. The other end thereof is connected to thefolding unit 110. The sheet is transported from a predetermined location(for example, the tray 26 or the manual feed tray 30) on the transportpath 20 to another location (for example, the image forming unit 104 orthe folding unit 110) on the transport path 20.

The tray 26 accommodates sheets. Although the two trays 26 are shown inFIG. 2, more trays 26 may be provided. The trays 26 accommodate, forexample, different types of sheets. The feed roller 28 feeds the sheetaccommodated in the tray 26 to the transport path 20. The sheets may bestacked on the manual feed tray 30.

In this example, the image forming apparatus 1 is an electrophotographicimage forming apparatus. The image forming unit 104 includes a tonerimage forming unit 22 and a fixing unit 24. The toner image forming unit22 forms a toner image on the sheet. Specifically, the toner imageforming unit 22 acquires image signals of respective colors of yellow(Y), magenta (M), cyan (C), and black (K) that are generated based onimage data of the respective colors of Y, M, C, and K. The toner imageforming unit 22 includes developing units 32Y, 32M, 32C, 32K, a transferbelt 34, a transfer roller 36, and a roller 138. The toner image formingunit 22 forms toner images of the respective colors of Y, M, C, and K onphotoconductor drums 38Y, 38M, 38C, and 38K with the developing units32Y, 32M, 32C, and 32K based on the acquired image signals, andsuperimposes the formed toner images on the transfer belt 34. Thetransfer belt 34 is wound around plural rollers including the transferrollers 36 near the transport path 20. The transfer belt 34 isrotationally driven as an intermediate image carrier. The transfer belt34 transfers the superimposed toner images onto the sheet. The transferbelt 34 is in contact with the photoconductor drums 38Y, 38M, 38C, and38K provided in the developing units 32Y, 32M, 32C, and 32K. Thetransfer roller 36 and the roller 138 sandwich the sheet and thetransfer belt 34, and transfer the toner image of the transfer belt 34onto the sheet. The transfer roller 36 faces the roller 138. The sheetis transported between the transfer roller 36 and the roller 138 on thetransport path 20. The fixing unit 24 fixes the toner image formed onthe sheet to form an image on the sheet. The fixing unit 24 includes apair of fixing rollers 40. The fixing unit 24 heats the sheet whileapplying pressure thereon in a state where the sheet transported betweenthe fixing rollers 40 is sandwiched by the fixing rollers 40.

The image reader 105 includes the automatic transport unit 44, anexposure optical system 50, and a solid-state imaging element CCD 56.The image reader 105 is located below a platen glass PG. The automatictransport unit 44 transports a sheet stacked on a sheet feeding tray 46to the image reader 105. The automatic transport unit 44 includes thesheet feeding tray 46, platen rollers 48, and a sheet discharge tray 49.The sheets whose images are to be read are stacked in the sheet feedingtray 46. The stacked sheet is fed from the sheet feeding tray 46 to theplaten rollers 48. The platen rollers 48 transport the fed sheet ontothe platen glass PG. The sheet is discharged to the sheet discharge tray49 after the image reading is completed. Although illustration anddescription of a detailed configuration of the image reader 106 areomitted, the image reader 105 can read both sides of the sheet.

The exposure optical system 50 reads the image of the sheet.Specifically, the exposure optical system 50 emits light from a lightsource 52 to the sheet fed onto the platen glass PG or a sheet that theuser places on the platen glass PG, and receives reflected light fromthe sheet. The solid-state imaging element CCD 56 converts the receivedreflected light into an electric signal. The exposure optical system 50includes the light source 52 and plural mirrors. When an image of thesheet that is placed on the platen glass PG by the user is read, theexposure optical system 50 moves to scan the sheet.

The folding unit 110 includes a folding mechanism 18 and a dischargetray 58. The folding mechanism 18 folds the sheet based on theinstruction input by the user. The folded sheet is discharged to thedischarge tray 58.

In the folding position adjustment process, even if the foldingdeviation amount is detected, the sheet may be read with the sheet stillfolded and it may not be known which surface of the sheet is being read.In this case, a direction in which a folding deviation occurs cannot bedetermined, and a correction direction cannot be determined. Therefore,the image forming apparatus 1 addresses this issue.

2. Operation

FIG. 3 is a flowchart of an example of the folding position adjustmentprocess performed by the image forming apparatus 1. The image formingapparatus 1 is, for example, a commercial printer that prints a largeamount of booklets such as brochures. When the user wants to adjust afolding deviation of a sheet, the image forming apparatus 1 prints atest print adjustment sheet, and detects a folding deviation amountusing the adjustment sheet before printing a sheet used for an actualbooklet. Here, the “adjustment sheet” refers to a sheet used for thefolding position adjustment process. The image forming unit 104 forms,on the adjustment sheet, a pattern image that facilitates detecting of afolding line. Alternatively, the image forming unit 104 may not form anyimage on the adjustment sheet, or may form contents such as charactersand images to be printed on the actual booklet. When the actual bookletis created by binding, for example, 5 sheets, the number of theadjustment sheet may be 1 or may be 5.

In step S1, the UI 103 receives a user's input of an instruction tocreate an adjustment sheet creation. This creation instruction may beinput by the user from, for example, a personal computer (hereinafterreferred to as “PC”) connected to a network. The creation instructionincludes folding manner information. Here, the “folding mannerinformation” refers to information including an identifier of thefolding manner and an identifier of a sheet.

FIGS. 4A to 4C are diagrams showing examples of menu screens in thefolding position adjustment process displayed on the UI 103. The UI 103first displays a menu screen. FIG. 4A is a diagram showing an example ofthe menu screen. On a screen 401, for example, displayed is a list ofitems that the user can set in the image forming apparatus 1. The userselects a desired process, here, “folding position adjustment”. The UI103 receives the selection of the “folding position adjustment” from theuser.

When the user inputs the selection of the “folding position adjustment”,the UI 103 then displays a screen for the user to select a sheet foldingmanner. FIG. 4B is a diagram showing an example of the screen thatallows the user to select the sheet folding manner. On a screen 402,displayed is a list of folding manners that are available in the foldingunit 110, such as “half-fold” and “tri-fold”. The UI 103 receives aselection of the folding manner from the user.

When the user inputs a selection of the “sheet folding manner”, the UI103 then displays a screen that allows the user to select a sheet type.FIG. 4C is a diagram showing an example of the screen that allows theuser to select a sheet type. On a screen 403, displayed is a list oftypes of sheets accommodated in the trays 26, such as “tray 1: A4” and“tray 2: A3”. The UI 103 receives a selection of the sheet type from theuser.

When the user inputs a selection of the “sheet type”, the UI 103 thenreceives a user's input of an instruction to create an adjustment sheet.On the screen of FIG. 4C, an UI object for instructing to create theadjustment sheet, for example, a start button is displayed. When thestart button is touched by the user, the UI 103 receives the touching asthe instruction to create the adjustment sheet. The controller 101starts creating the adjustment sheet.

In step S2, the folding unit 110 folds the sheet in the selected foldingmanner. For example, when “half-fold” is selected, the folding unit 110folds the sheet at a reference folding position corresponding to thehalf-fold. In another example, when “tri-fold” is selected, the foldingunit 110 folds the sheet at a reference folding position correspondingto the tri-fold. The storage 102 stores the reference folding positionfor each sheet folding manner and each sheet type.

In step S3, the UI 103 displays a guide screen. Here, the “guide screen”refers to a screen that prompts the user to place the adjustment sheeton the image reader 105. FIG. 5 is a diagram showing an example of theguide screen that prompts the user to place the adjustment sheet on theplaten glass. A guide screen 501 includes, for example, an instructionsuch as “Place the adjustment sheet on the platen glass withoutunfolding the adjustment sheet”, and an UI object for instructing toread the adjustment sheet, for example, a start button. According to theguidance, the user takes out the adjustment sheet from the dischargetray 58 and places the adjustment sheet on the image reader 105. On theguide screen, an UI object for starting reading of the adjustment sheet,for example, the start button is displayed. When the start button istouched by the user, the UI 103 receives the touching as an instructionto read the adjustment sheet.

When the UI 103 receives the input of the reading instruction, the imagereader 105 starts reading the adjustment sheet in step S4.

In step S5, the controller 101 detects the folding deviation amount. Amethod of detecting the folding deviation amount will be described. Todetect the folding deviation amount, the controller 101 uses the imageof the adjustment sheet read by the image reader 105.

FIGS. 6A to 6C are diagrams showing an example of reading a half-foldedsheet. The controller 101 detects the folding deviation amount based onsheet edges, an actual folding position, and a folding length appearingon the image. Here, the “sheet edge” refers to a side constituting anedge of the sheet. Here, among sheet edges on four sides, consider onlysheet edges on two sides that are substantially parallel to the foldingline. The “folding length” refers to the shortest length from a sheetedge to the reference folding position on a folded sheet.

FIG. 6A shows a cross section perpendicular to a surface of the platenglass PG when viewed from a direction of the actual folding position. Ofsurfaces of the folded sheet, a surface facing the platen glass PG willbe referred to as a “front surface”, and an opposite surface to thefront surface will be referred to as a “back surface”. FIG. 6B shows animage of the front surface, and FIG. 6C shows an image of the backsurface.

The controller 101 analyzes the image obtained by reading the sheet andspecifies a line that is inside the sheet (that is, inside an outershape of the sheet) and extends from one end of the sheet to another endof the sheet. For example, the storage 102 stores a table in which anidentifier of the folding manner, a surface to be read, and a lineappearing inside the sheet are associated with one other.

FIG. 7 is a table showing a relationship among lines obtained by imageanalysis, a sheet edge(s), and a folding line(s). Here, the “divisionnumber” refers to the number of areas (per surface) into which a surfaceis divided by folding the sheet. For example, in half fold, one surfaceof the sheet is divided into two areas. The controller 101 specifies thesheet edges and the folding line(s) with reference to the folding mannerinformation and the table. In most cases, it would be possible to detecta line in a region inside the outer shape of the sheet (morespecifically, a line extending from one end to another end andsubstantially parallel to one side of the outer shape of the sheet;hereinafter referred to as a “line inside the sheet”) on at least one ofthe front surface or the back surface. The controller 101 specifies, byreferring to the table of FIG. 7, which each of (i) a side that issubstantially parallel to and closer to the detected inside line amongthe sides constituting the outer shape of the sheet on the surface onwhich at least the line inside the sheet is detected and (ii) a sidethat is substantially parallel to and farther away from the detectedinside line among the sides constituting the outer shape of the sheet onthe surface on which at least the line inside the sheet is detectedcorresponds to a sheet edge or a folding line.

For example, as in the example of FIGS. 6A and 6B, when a sheet ishalf-folded, the line inside the sheet appears only on either the frontsurface or the back surface. According to the table, the controller 101defines a surface on which the line inside the sheet is detected as a“first surface”, and a surface opposite to the first surface as a“second surface”. Whether a front surface of the read image correspondsto the first surface or the second surface and whether a back surface ofthe read image corresponds to the first surface or the second surfacedepend on an orientation of the sheet when the sheet is placed on theplaten glass PG. In the example of FIG. 6B, the controller 101 specifiesa side (that is, a sheet edge 603) closer to an inside line 601 (thatis, one sheet edge) on the first surface as another sheet edge, andspecifies a farther side (that is, a folding line 602) as a foldingline.

FIGS. 8A to 8C are diagrams showing an example of reading a 6-pageaccordion folded sheet. FIG. 8A shows a cross section perpendicular tothe platen glass PG and perpendicular to the folding line of the sheet.FIG. 8B shows a read image of a front surface, and FIG. 8C shows a readimage of a back surface. Since the folding manner is 6-page accordionfold, lines inside the sheet appear on both the front surface and theback surface. According to the table in FIG. 7, the controller 101defines one surface as the second surface. The controller 101 specifiesa side (that is, a folding line 803) closer to an inside line 801 (thatis, one sheet edge) on the first surface as one folding line, andspecifies a farther side (that is, a folding line 802) as anotherfolding line. The other sheet edge 804 is hidden and is invisible on thefirst surface, but is visible on the second surface. The table of FIG. 7is premised on that when the sheet is unfolded, lines are arranged in anorder of a sheet edge 1, a folding line 1, a folding line 2, and a sheetedge 2 from the sheet edge 1.

Then, how to detect the folding deviation amount and how to adjust thefolding position will be described. First, the controller 101 specifiesthe reference folding position. For example, when a sheet is half-folded(that is, a surface is divided into two areas), the reference foldingposition is a position at which the sheet is divided in half, that is, amidpoint of a side perpendicular to the folding line.

In the example of FIG. 6B, a reference folding position of the foldingline 602 is a midpoint of a side perpendicular to the folding line 602(in a state where the sheet is unfolded). That is, a distance d1 fromthe folding line 602 to the sheet edge 601 and a distance d2 from thefolding line 602 to the sheet edge 603 are ideally equal to each other.However, distances actually measured in the example of FIG. 6B ared1<d2. A folding deviation amount Δd is Δd=d2−d1. The controller 101adjusts the folding position such that the folding deviation amountdecreases and ideally becomes zero.

In the example of FIG. 6B, the controller 101 may simply move thefolding line 602 to approach the sheet edge 603. For example, anapproaching amount, that is, an adjustment amount δ, is δ=Δd/2.

In the example of FIG. 6C, a reference folding position of the foldingline 602 is a bisecting point on a side perpendicular to the foldingline 602 (in a state where the sheet in unfolded). In this case, it isnecessary to know a length of the side perpendicular to the folding line602 in a state where the sheet is unfolded. However, when one surface(that is, either the first surface or the second surface) of thehalf-folded sheet is read and only one sheet edge appears on the readsurface (that is, when an image obtained by reading the sheet is onlythe image shown in FIG. 6C), one sheet edge 601 is hidden and isinvisible. As a result, the distance d1 from the folding line 602 to thesheet edge 601 cannot be measured. In this case, the controller 101specifies the length of the side of the sheet (that is, d1+d2) by usingthe identifier of the sheet included in the folding manner information.Specifically, the storage 102 stores information that associates theidentifier of the sheet and the length of the side of the sheet witheach other. The controller 101 specifies the length of the side of thesheet with reference to this information. The controller 101 adjusts thefolding position so as to approach a position at which the specifiedlength of the side is divided in half. The approaching amount, that is,the adjustment amount δ is similar to that in the example of FIG. 6B.

In the example of FIGS. 8A to 8C, a reference folding position of thefolding line 802 is a trisection point on a side perpendicular to thefolding line 802 (in a state where the sheet in unfolded). In this case,it is necessary to know a length of the side perpendicular to thefolding line 802 in a state where the sheet is unfolded. However, whenthe sheet is 6-page accordion folded as in the example of FIG. 8B, onesheet edge 804 is hidden and is invisible. As a result, the length ofthe side perpendicular to the folding line 802 cannot be measured. Inthis case, the controller 101 specifies the length of the side of thesheet by using the identifier of the sheet included in the foldingmanner information. Specifically, the storage 102 stores the informationthat associates the identifier of the sheet and the length of the sideof the sheet with each other. The controller 101 specifies the length ofthe side of the sheet with reference to this information. The controller101 adjusts the folding position so as to approach a position at whichthe length of the specified side is divided into thirds. It is notedthat the controller 101 cannot specify a sheet edge on the surface shownin FIG. 8B only based on an image read from a surface where only onesheet edge appears as shown in FIG. 8C. Thus, depending on the foldingmanner, the folding deviation amount cannot be detected only based on animage of one surface.

FIGS. 9A to 9F are diagrams showing examples of sheet folding manners.FIGS. 9A to 9F show half-fold, tri-fold (6-page gate fold), 6-pageaccordion fold (Z-fold), 8-page gate fold, double parallel fold, and8-page accordion fold (W-fold), respectively.

The half-fold (see FIG. 9A), tri-fold (see FIG. 9B), and 6-pageaccordion fold (Z-fold) (see FIG. 9C) are examples of a folding mannerthat allows detecting of the folding deviation amount without unfoldingthe sheet. On the other hand, the 8-page gate fold (see FIG. 9D), doubleparallel fold (see FIG. 9E), and 8-page accordion fold (W-fold) (seeFIG. 9F) are examples of the folding manner that does not allowdetecting of the folding deviation amount with the sheet folded.

The present exemplary embodiment is used in the “folding manner thatallows detecting of a folding deviation amount without unfolding asheet”. Here, the “folding manner that allows detecting of the foldingdeviation amount without unfolding the sheet” is a folding manner thatallows specifying of sheet edges and a folding length at least in animage obtained by reading one surface of a folded sheet. An example ofthis folding manner is a folding manner in which the number of foldinglines on the sheet is two or less. On the other hand, the “foldingmanner that does not allow detecting of the folding deviation amountcannot unless the sheet is unfolded” is a folding manner that does notallow specifying of a sheet edge nor a folding length in images obtainedby reading both sides of a folded sheet (for example, sheet edges arehidden and are invisible). An example of this folding manner is afolding manner in which the number of folding lines on the sheet isthree or more.

In step S6, the controller 101 calculates an adjustment value forcorrecting the folding deviation, based on the read image of theadjustment sheet. Here, the “adjustment value” indicates a length bywhich the controller 101 moves the folding position to decrease thefolding deviation amount. Specifically, the controller 101 specifies theposition(s) of the sheet edge(s), specifies the actual foldingposition(s), and measures the folding length(s), based on the readimage.

The controller 101 (specifically, the detector 109) calculates theadjustment value based on the specified position(s) of the sheetedge(s), the specified actual folding position(s), and the measuredfolding length(s).

In the example of FIG. 6B, the adjustment value for half-fold isobtained as follows.

Folding Length=50

d1=40 (from sheet edge 601 to actual folding position (that is, foldingline 602))

d2=60 (from actual folding position (that is, folding line 602) to sheetedge 603)

Folding Deviation Amount Δd=60−40=20

Adjustment Amount δ=20/2=10

In the example of FIG. 6C, the adjustment value for half-fold isobtained as follows.

Reference Folding Length=100

d2=60 (from actual folding position (that is, folding line 602) to sheetedge 603)

d1=100−60=40

Folding Deviation Amount Δd=60−40

Folding Deviation Amount Δd=20

Adjustment Amount δ=20

Refer back to FIG. 3 again. In step S7, the controller 101 adjusts thefolding unit 110 based on the calculated adjustment value such that thefolding deviation amount decreases, so as to adjust the foldingdeviation.

In the folding position adjustment process, it is unknown whichdirection the user places the sheet to face. Therefore, when it cannotbe specified whether the read image is of the first surface or thesecond surface, a direction in which a folding deviation occurs cannotbe discriminated (that is, a correction direction cannot be determined).

FIG. 10 is a flowchart of an example of a process of determining thecorrection direction in the folding position adjustment performed instep S5 when an image of only one of the first surface and the secondsurface is read. This process is performed, for example, when half-foldis selected. The process is performed, for example, between steps S5 andS6.

In step S101, the controller 101 (specifically, the discrimination unit106) specifies, based on an identification image that appears on theread image, whether the read surface is the first surface or the secondsurface. FIG. 11 is a table showing a relationship among identificationimages obtained by image analysis, the first surface, and the secondsurface.

The controller 101 specifies, based on the identification image thatappears on the image and the table, whether the read image is of thefirst surface or the second surface. The storage 102 stores informationin which a type of the identification image is associated with the firstsurface or the second surface. The discrimination unit 106 reads, fromthe storage 102, information corresponding to the identification imageappearing on the image, and determines whether the surface on which thefolding deviation occurs is the first surface or the second surface.

In the example of FIGS. 6A to 6C, for example, when a firstidentification image 504 “▪” (a square filled with black) appears on theread image, the controller 101 specifies the read image as the firstsurface.

In step S102, the controller 101 determines whether a folding deviationappears on the read image. When the controller 101 determines that thefolding deviation appears on the read image (step S102: YES), theprocess proceeds to step S103.

In step S103, the controller 101 determines a direction in which afolding length of the first surface increases (that is, a direction fromthe folding position toward a sheet edge on the second surface) to bethe correction direction.

On the other hand, if the folding deviation does not appear on the readimage (step S102: NO), the process proceeds to step S104.

In step S104, the controller 101 measures an actual folding length ofthe read surface. The “actual folding length” refers to the shortestlength from the sheet edge to the actual folding position of the sheet,which is folded by the folding unit 110, with the sheet folded.

In step S105, when a relationship between the measured actual foldinglength and the reference folding length meets

Actual Folding Length<Reference Folding Length

(step S105: YES), the process proceeds to step 103, that is, thecontroller 101 determines a direction in which a folding length of thefirst surface increases to be the correction direction (step S103).

On the other hand, in step S105, when the relationship between themeasured actual folding length and the reference folding length does notmeet

Actual Folding Length<Reference Folding Length

(that is, the relationship meets “Actual Folding Length>ReferenceFolding Length”) (step S105: NO), the process proceeds to step S106.

In step S106, the controller 101 determines a direction in which thefolding length of the first surface decreases (that is, a direction fromthe folding position toward a sheet edge on the first surface (in otherwords, a direction in which a folding length of the second surfaceincreases)) to be the correction direction.

FIG. 12 is a flowchart of an example of a process of determining thecorrection direction in the folding position adjustment performed instep S5 when images on both the first and second surfaces are read. Thisprocess is performed when selected is a folding manner (such as tri-foldand 6-page accordion fold) in which the number of folding lines is twoor more. The process is performed, for example, between steps S5 and S6.

In step S201, the controller 101 (specifically, the discrimination unit106) specifies, based on identification images that appear on the readimages, whether each read surface is the first surface or the secondsurface. FIG. 11 is a table showing a relationship among identificationimages obtained by image analysis, the first surface, and the secondsurface.

The controller 101 specifies, based on the identification image thatappears on the image and the table, whether the read image is of thefirst surface or the second surface. The storage 102 stores informationin which a type of the identification image is associated with the firstsurface or the second surface. The discrimination unit 106 reads, fromthe storage 102, information corresponding to the identification imageappearing on the image, and determines whether the surface on which thefolding deviation occurs is the first surface or the second surface.

An example in which images shown in FIGS. 6B and 6C are read will bedescribed below. Since a mark “▪” (a square filled with black) appearson one surface as shown in FIG. 6B, the controller 101 identifies thissurface as the first surface. The controller 101 also specifies theother surface having the image shown in FIG. 6C, as the second surface.

Similarly, an example in which images shown in FIGS. 8B and 8C are readwill be described below. Since the mark “▪” appears on one surface asshown in FIG. 8B, the controller 101 specifies this surface as the firstsurface. Also, since a mark “•” (a circle filled with black) appears onthe other surface as shown in FIG. 8C, the controller 101 specifies thissurface as the second surface. When a sheet is 6-page accordion folded,folding deviations may occur on both the first and second surfaces ofthe sheet. However, based on the identification images formed on bothsurfaces, the controller 101 can specify whether each folding deviationoccurs on the first surface or the second surface.

Refer back to FIG. 12 again. In step S202, the controller 101 determineswhether the folding deviation appears on the specified first surface.When determining that the folding deviation appears on the read image(step S202: YES), the controller 101 causes the process to process tostep S203.

In step S203, the controller 101 determines a direction in which afolding length of the first surface increases (that is, a direction fromthe folding position toward the sheet edge on the second surface) to bethe correction direction.

On the other hand, when determining that no folding deviation appear onthe specified first surface (step S202: NO), the controller 101 causesthe process to process to step S204.

In step S204, the controller 101 determines a direction in which afolding length of the second surface increases (that is, a directionfrom the folding position toward the sheet edge on the first surface) tobe the correction direction.

FIGS. 13A and 13B are diagrams showing an example of a state in which atri-folded sheet on which identification images are formed is unfolded.FIG. 13A is a diagram showing an example of one surface of thetri-folded sheet in the unfolded state. FIG. 13B is a diagram showing anexample of the other surface of the tri-folded sheet in the unfoldedstate. When the number of folding lines is two, the sheet is dividedinto three areas. When the sheet is tri-folded, surfaces which are outersurfaces of the folded sheet are (i) a surface of one of two partslocated on both sides of the sheet that is divided into three parts, and(ii) a surface of the middle part. The image forming unit 104 formsdifferent identification images (for example, “▪” and “•”) on portionsof the sheet that become such surfaces, respectively. When the sheet istri-folded, plural identification images are formed on surfaces thatbecome the same surface (that is, one side) of the sheet in the unfoldedstate.

FIGS. 14A and 14B are diagrams showing examples of front and backsurfaces of a 6-page accordion folded sheet on which identificationimages are formed. FIG. 14A is a diagram showing an example of the frontsurface (that is, one surface) of the 6-page accordion folded sheet.FIG. 14B is a diagram showing an example of the back surface (that is,the other surface) of the 6-page accordion folded sheet. When a sheet is6-page accordion folded, surfaces which are outer surfaces of the foldedsheet are two surfaces of two parts located on both sides of the sheetthat is divided into three parts. The image forming unit 104 formsdifferent identification images (for example, “▪” and “•”) on portionsof the sheet that correspond to such surfaces, respectively. When thesheet is 6-page accordion folded, identification images are formed onboth surfaces of the sheet in an unfolded state.

3. Modifications

The present disclosure is not limited to the exemplary embodimentsdescribed above. Various modifications may be made. Hereinafter, acouple of modifications will be described. Two or more items describedin the following modifications may be used in combination.

3-1. Identification Image

The image forming unit 104 may form other identification images on thesheet instead of forming the identification images such as “▪” and “•”on the sheet. FIGS. 15A to 15F are diagrams showing examples ofidentification images formed on the sheet. FIG. 15A is a diagram showingan example of a sheet on which an identification image “▪” is formed onthe first surface. FIG. 15B is a diagram showing an example of a sheeton which an identification image “▪” is formed on the first surface andan identification image “•” is formed on the second surface. FIG. 15C isa diagram showing an example of a sheet on which an identification image“

” (leftward arrow) is formed on the first surface and an identificationimage “→” (rightward arrow) is formed on the second surface. Tips of thearrows indicate directions in which the sheet edges are located. FIG.15D is a diagram showing an example of a sheet on which anidentification image that is “QR code (registered trademark)” is formedon the first surface. The QR code is an example of an image showing thefolding manner information. FIG. 15E is a diagram showing an example ofa sheet on which an identification image “two line segments” is formed.The two line segments are formed, for example, so to straddle thefolding line. The two line segments have different slopes such thatwhile the two line segments do not intersect with each other on thefirst surface, the two line segments intersect with each other on thesecond surface. FIG. 15F is a diagram showing an example of a sheet onwhich identification images that are “punch holes” are formed on thefirst surface.

3-2. Automatic Sheet Reading

When a folding manner that allows detecting of the folding position withthe sheet folded, the image forming apparatus 1 may automaticallytransport the sheet to the image reader 105 instead of having the userplace the sheet. In this case, the UI 103 may not display a guidescreen.

3-3. Hardware Configuration

The hardware configuration of the image forming apparatus 1 is merely anexample. Any hardware configuration may be used. For example, the imageforming apparatus 1 and the folding device (that is, the folding unit110) may be different devices.

3-4. Others

The program to be executed by the controller 101 may be provided in aform of a recording medium such as an optical disc that stores theprogram. Alternatively, the program to be executed by the controller 101may be downloaded to a computer via a communication line such as theInternet, installed in the computer and made available.

In the exemplary embodiments above, the term “processor” refers tohardware in a broad sense. Examples of the processor include generalprocessors (e.g., CPU: Central Processing Unit) and dedicated processors(e.g., GPU: Graphics Processing Unit, ASIC: Application SpecificIntegrated Circuit, FPGA: Field Programmable Gate Array, andprogrammable logic device).

In the exemplary embodiments above, the term “processor” is broad enoughto encompass one processor or plural processors in collaboration whichare located physically apart from each other but may work cooperatively.The order of operations of the processor is not limited to one describedin the exemplary embodiments above, and may be changed.

The foregoing description of the exemplary embodiments of the presentdisclosure has been provided for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit thedisclosure to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to practitioners skilled in the art. Theexemplary embodiments were chosen and described in order to best explainthe principles of the disclosure and its practical apps, therebyenabling others skilled in the art to understand the disclosure forvarious embodiments and with the various modifications as are suited tothe particular use contemplated. It is intended that the scope of thedisclosure be defined by the following claims and their equivalents.

What is claimed is:
 1. An information processing apparatus comprising: aprocessor that is configured to: read an image of at least one of afirst surface or a second surface of a medium with the medium folded;discriminate whether the image is of the first surface or the secondsurface based on an identification image in the image; specify, based onthe image, a surface on which a folding deviation occurs; andautomatically determine a correction direction of the folding deviationaccording to whether the surface on which the folding deviation occursis the first surface or the second surface and adjust a foldingmechanism based on the automatically determined correction direction sothat the folding deviation decreases.
 2. The information processingapparatus according to claim 1, wherein the medium is a half-foldedmedium, one surface of the first surface or the second surface of thehalf-folded medium is read, and the correction direction is determinedaccording to (i) the identification image on the one surface and (ii)the folding deviation.
 3. The information processing apparatus accordingto claim 2, wherein when the one surface is the surface on which thefolding deviation occurs, a direction opposite to a sheet edge side onthe one surface is determined to be the correction direction.
 4. Theinformation processing apparatus according to claim 3, wherein acorrection amount is detected by measuring a folding length of themedium in a direction intersecting the folding deviation.
 5. Theinformation processing apparatus according to claim 3, wherein acorrection amount is detected based on the folding deviation.
 6. Theinformation processing apparatus according to claim 2, wherein when theone surface is not the surface on which the folding deviation occurs, adirection toward a sheet edge side on the one surface is determined tobe the correction direction.
 7. The information processing apparatusaccording to claim 6, wherein a correction amount is detected bymeasuring a folding length of the medium in a direction intersecting thefolding deviation.
 8. The information processing apparatus according toclaim 6, wherein a correction amount is detected based on the foldingdeviation.
 9. The information processing apparatus according to claim 2,wherein a correction amount is detected by measuring a folding length ofthe medium in a direction intersecting the folding deviation.
 10. Theinformation processing apparatus according to claim 2, wherein acorrection amount is detected based on the folding deviation.
 11. Theinformation processing apparatus according to claim 1, wherein acorrection amount is detected by measuring a folding length of themedium in a direction intersecting the folding deviation.
 12. Theinformation processing apparatus according to claim 1, wherein themedium is a half-folded medium, both surfaces of the first surface andthe second surface of the half-folded medium are read, and thecorrection direction is determined according to (i) the identificationimage on the one of the first and second surfaces and (ii) the foldingdeviation.
 13. The information processing apparatus according to claim1, wherein the medium is a tri-folded medium, a first identificationimage is formed on the first surface of the medium, a secondidentification image is formed on the second surface, both surfaces ofthe first surface and the second surface of the tri-folded medium areread, and the correction direction is determined according to the firstidentification image, the second identification image, and the foldingdeviation.
 14. The information processing apparatus according to claim13, wherein when the folding deviation is larger than a target foldingdeviation, a direction toward a sheet edge side is determined to be thecorrection direction.
 15. The information processing apparatus accordingto claim 13, wherein when the folding deviation is smaller than a targetfolding deviation, an opposite direction to a direction toward a sheetedge side is determined to be the correction direction.
 16. Theinformation processing apparatus according to claim 1, wherein acorrection amount is detected based on the folding deviation.
 17. Anon-transitory computer readable medium storing a program that causes acomputer including a processor to execute information processing, theinformation processing comprising: reading an image of at least one of afirst surface or a second surface of a medium with the medium folded,discriminating whether the image is of the first surface or the secondsurface based on an identification image in the image; specifying, basedon the image, a surface on which a folding deviation occurs; andautomatically determining a correction direction of the foldingdeviation according to whether the surface on which the foldingdeviation occurs is the first surface or the second surface andadjusting a folding mechanism based on the automatically determinedcorrection direction so that the folding deviation decreases.